by Peter Grant
"Don't tell me the party was too much for your delicate spacer's constitution?" the Bosun asked with a grin.
"At least you had something of your own to celebrate, too," Steve said, nodding to the brand-new insignia of a Bosun's Mate First Class on Tomkins' left sleeve, crossed anchors inside an upturned gold laurel half-wreath. "I think your students are probably a lot worse off than you are - at least, we haven't seen any of them in here yet."
"I reckon someone must have slipped a mickey into my drink," the hapless Tomkins moaned.
"Which drink would that have been - the tenth, fifteenth or twentieth?"
"Oh, shut up!"
"Funny, the Bosun just told me to do the same thing!" All three laughed, although Tomkins had to clutch his aching head as he did so.
The waiter returned, bearing a tray carrying a carafe of piping-hot coffee and a glass filled with a steaming, bubbling, roiling, opaque liquid. Tomkins held his nose, tossed it back, and shuddered. "Urgh! That's ghastly!"
"It does the job, though," the Bosun pointed out as the waiter filled Tomkins' cup, then refilled his and Steve's. "Give it a moment to take effect before you drink your coffee."
"I'm surprised they had it available," Steve remarked, adding cream and sweetener to his coffee. "It's not on the menu, after all."
"They're used to hungover spacers in this joint," Tomkins said, already a little less groggily. "Most eateries in orbital terminals keep some on hand."
The Bosun glanced at the clock on the wall. "The skipper's shuttle should be getting in soon. When are they releasing Cabot to us?"
Steve paused as he lifted his coffee cup to his mouth. "They said fourteen today. She ran trials last week, including a hyper-jump, then they brought her back to the dockyard for a couple of minor adjustments."
"That's normal. Everyone should have arrived by then, so as soon as we've taken her out for a full-power test run and the skipper's signed off on the yard work, we can start loading. Any idea what the freight broker's lined up for us?"
"He said there was a small cargo for Rosalva," Tomkins said, sipping his coffee. "It's only a couple of thousand containers, but they've apparently got a lot of stuff there to ship to multiple destinations. He'd contracted with another freighter for the job, but a robotic cargo shuttle had a computer fart last week. It lost remote telemetry and collided with her, very hard."
Cardle winced. "How many casualties, and how bad?"
"By some miracle, no-one in the hold work party was hurt, but I bet they all had to sanitize their spacesuits afterwards!" Steve and the Bosun sniggered, but sympathetically. They knew how scared they'd have been under the same circumstances - and with good reason. Hard vacuum was utterly intolerant of error and devoid of mercy.
Tomkins continued, "The shuttle ripped off one of the ship's cargo doors and ended up jammed into her hull, buckling two frames and several stringers. It's still stuck there. She's waiting for an open dockyard bay to make repairs - in fact, she'll probably take ours when Cabot moves out. The broker says if we can get to Rosalva by the twentieth, we can take her place and fill our holds for a multi-leg delivery."
The Bosun smiled. "That's more like it! We won't do much better than break even getting there, but if they've got a full load waiting for us, that'll make the trip worthwhile."
Tomkins beckoned the waiter. "I think I can stomach something now. Scrambled eggs on toast, please, and more coffee."
"Right away, Sir."
"And put another table next to ours," the Bosun added as he spied three more members of Cabot's crew entering the restaurant. "Another shuttle must have just pulled in. You're about to become the busiest server in the place!"
###
They were able to begin loading cargo four days later, after the skipper pronounced himself satisfied with a full-power test run. The spacers donned their spacesuits and assembled in the main passage outside the midships holds. The Bosun busied himself dividing them into teams to begin loading containers for Rosalva.
Cardle looked up from his electronic clipboard. "Maxwell, you haven't assisted the Loadmaster yet, have you?"
"No, Bosun."
"It's high time you did. You're a Second Class now, so you need to start learning what goes into his job. I'll call him to tell him you're coming. Get out of your work gear and stow it, then report to him."
"Aye aye, Bosun."
The Third Mate, Eddie Boals, who was also the ship's Loadmaster, was sitting at his specialized console in an alcove off the bridge. Steve came up behind him and coughed gently.
"What is it, Spacer?" Boals asked without turning his head, intent on his displays.
"Sir, I'm Maxwell. The Bosun said - "
"Oh, yes! He called me about you. Here, take a seat." As Steve sat down beside him he continued, "At the moment I'm planning where to place cargo to optimize the ship's longitudinal stability."
"Yes, Sir. I recall learning during my training that longitudinal stability is very important when making a hyper-jump."
"That's putting it mildly!" Boals called up a three-dimensional diagram of Cabot. "Look here. Our midships point is calculated on three axes; front to back, top to bottom and side to side. Ideally we like to have our center of mass - of gravity, if you like - coincide with that point, so that the ship's perfectly balanced. With careful loading we can usually get it to within a few meters of where we want it on each of those axes. I've calculated the placement of those containers to optimize it. We'll finish the job by moving reaction mass between ballast tanks to fine-tune the adjustment.
"When the ship makes a hyper-jump, as you know, she's dragged into an artificial wormhole, a toroidal gravitic field generated ahead of her. It spits her out light-years ahead of where she started. Her longitudinal stability - in other words, the ship's tendency to continue in a straight line rather than pitch up or down, or yaw left or right, around her center of gravity - is absolutely critical for that maneuver.
"If our stability is out of whack by more than half a per cent, we might be pulled into the toroidal field off-course - in other words, at an angle. That would throw off our exit position. An error of only one degree would put us more than two hundred and sixty billion kilometers out of position at the end of a ten-light-year hyper-jump. If we're in deep space, navigating between planets, we can compensate for that in the next jump, but if our exit point was close to a star, or a black hole, or something like that, it might be a lot more tricky - you don't want to get too close, for obvious reasons! If the error is greater than two or three per cent, stresses on the ship's structure will become unsustainable. We'll be ripped apart, hull, cargo and crew." He shook his head vehemently. "I don't want to die any more than the next man, but I particularly don't want to die like that, thank you very much!"
"That makes two of us, Sir," Steve assured him very sincerely.
"There's a lot of material about the Loadmaster's job in the ship's library. I recommend you do a couple of hypno-study modules to learn the calculations involved - and give them more than passing attention. This is a critical function. If the Loadmaster gets things wrong, ships and people die!"
Steve spent the rest of the morning watching Boals at work and asking questions. The man operated like the conductor of an orchestra, checking the loaded mass of each container, directing spacers to put them in specific locations in the hold or move stacks of containers here and there until he was satisfied. As each section of hold was finished, the crew used restraints to strap everything in place and verify that it would be secure against the inertial forces generated by space flight. The size and quantity of straps, clamps, magnets and other securing devices illustrated all too clearly the potential magnitude of those forces.
"How do warships manage to balance their load, Sir?" he asked at one point. "I mean, aboard a freighter you've got holds spread the length and breadth of the ship. It's easy to move things around. Warships don't have so many or such big cargo spaces, so how do they fine-tune their longitudinal stability?"
"It has to be designed into them on the drawing board. It's a very complex problem. A warship's missiles are usually more than ten per cent of her loaded mass, and her consumable supplies are at least as much again. Once she's fired or used those things, she must still be longitudinally stable, even though her mass has been greatly reduced. What the designers do is position the missile cells in the middle third of the ship, so that when they're fired there isn't too much mass lost from fore or aft. They also fire partial missile salvos using a pattern across all of the cells, rather than taking all of them from one part of the main battery. That helps keep the ship's overall mass evenly distributed.
"As for consumables, a warship's storage is spread along the length of the ship. She tries to stow and use her stores in a balanced way. She has ballast tanks, like us, so she can distribute reaction mass to balance the ship. Taken in combination, those measures usually work."
"Er... you said 'usually', Sir. What if they don't work for some reason?"
The Third Mate shrugged. "Then the ship's in a world of hurt! She'll have to dump excess weight in order to restore stability, perhaps by firing off more of her missiles, or jettisoning an empty missile cell, or supplies, or reaction mass. Needless to say, no-one likes to do that, given the hazard to astrogation posed by space debris. Alternatively, another ship may be able to provide extra ballast. Absent either of those alternatives, the ship won't be able to hyper-jump safely. She'll be stuck where she is until another ship can bring her what she needs to solve the problem. If there are enemies around at the time, or if she doesn't have any way of sending for help, or doesn't have enough supplies to wait until help arrives... well, that's just her crew's horrible luck, I guess."
"I get it, Sir. Not a good position to be in."
"Not good at all!"
Another half-hour passed in silence as the Third Mate continued to calculate masses and balance points, and move the cargo accordingly. Steve watched closely, and occasionally used his PIA to look up a point in the ship's library.
During a brief pause, Boals turned to Steve. "You haven't yet spent any time on the bridge during passage, have you?"
"No, Sir. I did a three-month stint in Engineering, and another in hull maintenance."
"That makes sense. You were a Third Class until very recently, and those areas are less complex, better suited to entry-level spacers. However, you're a Second Class now, and you need to begin learning about the various consoles on the bridge that we use to operate the ship when she's under way. I'll have a word with the Bosun. I think you'll be best advised to start on the Navigation console for the next three months, then look at the Plot and Communications."
"Thank you, Sir. I'll look forward to it."
Chapter 17: May 17th, 2838 GSC
Cabot's bridge was quiet. The only sounds were the whisper of air from the ventilating ducts, and the occasional murmur of voices as the duty watch consulted among themselves.
"How do they work out the system boundary for each type of star, Sir?" Steve asked the Second Mate and Navigating Officer, Lieutenant Feeny. He was seated next to him, learning to operate the support functions of the Navigation console. "I know it's the distance from the star within which our hyper-jump's toroidal gravitic field might be disrupted by the star's own gravity, but I'm not sure why its distance from the star differs from system to system."
"It's a complex process," Feeny explained. "The system boundary's usually portrayed as an oblate spheroid, centered on the star. The star's type and mass affect its radius, which is usually around a billion kilometers, plus-or-minus about ten per cent. The system boundary would be a pure sphere but for the mass, number and positions of planets and asteroids. They normally occur along the plane of the system - the level upon which most objects orbit the star - so they extend the system boundary along the plane. That's also why we arrive below the plane, and depart a system above it. It's to avoid those minor gravitic influences."
"Why not arrive above and depart below the plane, Sir? Who decides?"
"The present system was codified by United Planets convention a couple of centuries ago, in order to avoid unexpected encounters between arriving and departing ships. It applies throughout the settled galaxy. Individual planets can and do regulate it even more strictly. If they have heavy starship traffic - like Old Home Earth or Vesta, for example - they divide their system into zones for ships arriving from or departing in various directions, with others reserved for intrasystem traffic. They publish their navigation requirements as Notices to Spacers. Being a Lancastrian ship, we get ours through the Board of Admiralty, which updates its Interstellar Pilot every quarter. Every starfaring planet or polity sends its updates to the Transport Directorate of the United Planets. They receive everyone's updates, consolidate them into quarterly reports, and circulate them to all settled planets and interstellar polities, who redistribute them as they see fit."
"I get it. Does Rosalva have any special regulations?"
"Funny you should ask that. Up until a few months ago they didn't, but according to the latest Admiralty update, they do now."
"They do?" Captain Volschenk asked from his command console, frowning. "Why wasn't I informed about them, Pilot?"
"I assumed you'd received the latest update signal at Bedford, Sir. It was addressed to Commanding Officers and Navigating Officers, as usual."
"I don't recall seeing it. I'll check on that. What are Rosalva's requirements?"
"Sir, the Interstellar Pilot advises that Rosalva's been having trouble with piracy. As a result, the planet's implemented a convoy system for arriving and departing spaceships. We'll emerge plus-or-minus fifty million clicks from their designated arrival point, which will be marked by a spacebuoy beacon, orbited by one of their patrol craft. We'll join it at the beacon, then wait to be escorted to planetary orbit along with any other arrivals, Sir. They run inward and outward convoys, one every second day."
Volschenk frowned. "That could delay us. When did they institute this policy?"
"According to the Interstellar Pilot it came into effect four months ago, Sir. They don't have many patrol craft, so this allows them to concentrate traffic and escorts together, rather than have to sweep their entire system for intruders."
"Very well. Prepare a course to the beacon as soon as you locate it after we arrive. We'll cruise over to it at low power. No sense in having to kill too much momentum if we're going to rendezvous with other ships."
"Aye aye, Sir."
"On a different note, I'm glad to hear you asking plenty of questions, Maxwell," the Captain observed. "That's how you learn - and it keeps the rest of us on our toes, answering them." A subdued chuckle ran around the Bridge watch.
"Yes, Sir," Steve agreed. "I must admit, astrogation's fascinating. It's so complex!"
"That it most certainly is. Are we ready for our final hyper-jump, Pilot?"
"Aye aye, Sir. Course and energy level have been transmitted to your console, Sir."
"Thank you."
The Captain reached for his harness and strapped himself into his seat as the rest of the Bridge watch did likewise. He scanned his displays rapidly, then donned his headset and microphone. He pressed a button on the console.
"Command to Engineering. I'm showing only 87.1% on the capacitor ring charge. Why isn't it at 100%?"
There was a pause. Lieutenant Feeny hurriedly switched his console's audio to the Command channel so he and Steve could follow the conversation through their headphones.
The voice that replied wasn't the Chief Engineer, but one of his senior techs. "Engineering to Command. Sir, we had to divert some reactor power to our two cargo shuttles, to power up their own reactors and check out their systems. They've been dormant all through our refit, and weren't used to load our cargo for this trip - we used Bedford's shuttles to do that. We wanted to check them out thoroughly before they had to fly again. 87.1% is still plenty for our final hyper-jump, Sir."
"Command to Engineering, I'm
aware of that, but you should have recorded the charging discrepancy in the exception log. I shouldn't have had to ask you about it."
"Engineering to Command, sorry about that, Sir. It won't happen again."
Steve mentally winced for the engineering tech. A rebuke like that would be automatically logged in the Captain's journal, and the Engineering Officer would see it along with all the other Heads of Department when he signed the journal each week. The tech responsible for the slip-up was going to be in for a severe chewing-out when he did.
"Very good. Break. Pilot, you gave me an energy level of 42.7% for our final hyper-jump. Was that based on a full capacitor ring charge, or our current level?"
"Current level, Sir."
"Very well. In future, if you see that the capacitor ring charge is at less than 100%, please notify me that the energy level you've calculated takes that into account. That way I don't have to ask unnecessary questions."
"Aye aye, Sir."
"Anything else I should know about?"
"Nothing from Navigation, Sir."
"Nothing from Communications, Sir."
"Nothing from the Plot, Sir."
"Very well."
Captain Volschenk issued the usual fifteen-minute warning, and the crew began the now-familiar routine of preparing for the next hyper-jump, the last of this journey. A quarter of an hour later, Steve felt a jolt in the pit of his stomach as Cabot was thrust through half a light year of empty space in the blink of an eye.
After a brief pause and a thorough scan of the Plot and his instruments, Feeny announced, "Sir, we've arrived at our planned position on Rosalva's system boundary. A navigation beacon has been detected, bearing from ship's head 007:019. Emissions match those published in the Interstellar Pilot for Rosalva's assembly beacon for arriving traffic. Three gravitic drive emission sources detected on the same bearing. Preliminary classification is one small patrol vessel and two merchant freighters. Recommend heading for the beacon at low power, Sir."
